Longtime fans of the Colorado Symphony Orchestra have literally watched Claude Sim grow up as a musician. He arrived as a fresh-faced, 21-year-old violinist out of Ohio’s Oberlin Conservatory of Music. Now 38, married and a father, Sim is the orchestra’s associate concertmaster and holder of the second violin seat.

But Sim’s taste in music ranges far beyond Rachmaninoff and Vivaldi.

He is part of a Denver jazz trio, has recorded an album of jazz standards and jammed onstage with banjo titan Béla Fleck. His eclectic ear has led him to venture into everything from the bluegrass of Bill Monroe to the French gypsy swing of Stephane Grappelli. For a decade, he was a soloist with the tango group Extasis.

He has appeared live and in the studio with Denver’s Devotchka, and shared the stage with rock band Guster, as well as Warren Haynes, guitarist for Gov’t Mule and the Allman Brothers Band.

All of this makes Sim a rather uncommon wearer of two hats: violinist by profession, fiddler for love of the form.

“Growing up, I would say I just had a really open mind listening to music,” he said on a recent afternoon, just after his CSO rehearsal ended under the soaring dome of the Boettcher Concert Hall at the Denver Performing Arts Complex. “When I was young, I didn’t draw boundaries in my head. It was equally exciting to go to a rock or a jazz concert.

“As long as there is some communication in the music, I’m happy.”

Sim is devoted to the violin. While he can talk about it in pragmatic terms, his sheer love for the instrument — and the places it can take player and listener — is always there.

“I think there’s a tactile kind of joy in playing the violin,” he said. “The music vibrates through your fingers and reverberates through your body.”

He paused, then laughed. “Of course, it can be a frustrating instrument, too.”

His mother taught piano — he took up that instrument and violin at age 3.

His father was a medical librarian.

“Music was always part of my childhood,” said Sim, who was brought up in the Chicago area. “I have to say, I didn’t always practice enough. Let’s just say I really enjoyed my childhood.”

Lucky for us, he stuck with the violin.

Most American job-holders work with new equipment that often gets replaced every couple of years, whether it’s a carpenter and his hammer or a computer programmer and her laptop.

Not Sim. His violin dates from 1759, crafted by a famed Venetian luthier named Michele Deconet. Sim bought it in Chicago, and while he shies from revealing the purchase price, he concedes that it was “more than I paid for my house.”

“It’s one of the sacrifices many musicians make, especially violinists,” Sim said of investing in a world-class instrument. “Financially, it sets you back many years. You eat lots of ramen. But there’s a reason for it if you’re really passionate about your art.”

Sim is a family man now, raising a daughter with his wife, Natalia, a piano teacher. Free time is scarce, because he is always studying scores, listening to recordings and playing his parts over and over so he will be ready for rehearsal.

Asked about his favorite classical piece, he neither hems nor haws.

“Gustav Mahler’s 2nd Symphony,” Sim said. “Now, a lot of people would say that’s like being asked to pick your favorite child. But in my case, hey, I have a favorite child.”

As for jazz, that’s a little different. Sim is a huge fan of Miles Davis, the late trumpet player, band leader and composer who bridged the eras between bebop and fusion. He particularly admires Davis’ second great quintet, the one with Wayne Shorter, Herbie Hancock, Ron Carter and Tony Williams.

“When you listen to Miles and a lot of jazz guys talking about Bach and Stravinsky as being real influences on them in terms of structure and harmonies, it’s really encouraging as a classical player,” Sim said. “To hear that is inspiring.”

He is also a fan of jazz pianist Keith Jarrett and crooner Tony Bennett.

Bluegrass also intrigues him. He heard Béla Fleck and the Flecktones many times when he lived in Chicago. The notion of playing with Fleck, whose musical vocabulary expanded exponentially in the past quarter century, never occurred to him.

“But the chance came to work with him and I jumped on it,” Sim recalled. “It was a life-changing moment for me. We played a duet, just him and me. The piece (‘Crooked Run’) was really a jam. It had a basic chart and form, but really went all over the map. It was a big challenge, but I did the best that I could.”

The two-man performance — done in June 2014 at the Montrose Pavilion as a highlight of Fleck’s appearance with the CSO — drew raves.

Sim has recorded an album of jazz standards, “Time With You.” And he has collaborated with the Vermeer Quartet, an acclaimed chamber group, and played with the Baltimore Symphony Orchestra. His jazz trio, with Dan Schwindt on guitar and Bijoux Barbosa on bass, plays around town.

And he found time to learn the mandolin, which is tuned the same as the violin. (He also played bass in a rock band in high school.)

But classical music remains his first love. Give him a time machine, and he would travel back and talk with the great composers: Brahms, Beethoven and Mahler, musicians he sees as au courant now as they were in their day.

“There’s a perception that classical music was always there,” Sim said. “It’s on this pedestal. But it’s actually kind of recent. Nijinsky’s ‘Rite of Spring’ literally caused a riot in the audience when it premiered. Now it’s part of the canon.”

He is cautiously optimistic about the future of the form.

“In Denver, seeing so many talented young people passionate about the music is encouraging,” Sim said. “But it’s a challenge to convince people that classical music matters.”

William Porter: 303-954-1877, wporter@denverpost.com or @williamporterdp

Sim on stage

Claude Sim, the versatile violinist and associate concertmaster for the Colorado Symphony Orchestra, will appear next month with his jazz trio.

Restaurant critic William Porter is a feature writer at The Denver Post, where he covers food, culture and people. He joined the news outlet in 1997. Before that, he spent 14 years covering politics and popular culture at The Phoenix Gazette and Arizona Republic. He is a native of North Carolina.